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Products => Test Equipment => Topic started by: K1JOS on April 21, 2017, 10:16:43 pm

Title: Rigol DSA-815 - Amplitude calibration
Post by: K1JOS on April 21, 2017, 10:16:43 pm
ANyone know how to adjust the power calibration?  My 815 is reading -1.5 dB on a NIST 50MHz 1 mW (0 dB) reference.  I did set the autocalibrate with no improvement.  I cannot find the "Acc Calibrate" as mention in the manual. 

Any advice appreciated

Jerry NY2KW
Title: Re: Rigol DSA-815 - Amplitude calibration
Post by: xrunner on April 22, 2017, 12:36:21 am
ANyone know how to adjust the power calibration?  My 815 is reading -1.5 dB on a NIST 50MHz 1 mW (0 dB) reference.  I did set the autocalibrate with no improvement.  I cannot find the "Acc Calibrate" as mention in the manual. 

Any advice appreciated

Jerry NY2KW

I have a DSA815. I just searched the manual for "Acc Calibrate" and did not find it. Where in the manual did you find that?
Title: Re: Rigol DSA-815 - Amplitude calibration
Post by: K1JOS on April 22, 2017, 01:08:37 am
Its in the March 2015 DSA 800 series User Manual page 161.  It was not in my original 2013 User Manual so I assumed added later in newer firmware.  I am running firmware v1.08 so I looked at the release notes from past firmware and it seems they added this after v 1.09.  Now I see they are up to 1.15 so maybe I should update the firmware.    Have to read how not to lose my 'licenses'.

Jerry NY2KW
Title: Re: Rigol DSA-815 - Amplitude calibration
Post by: xrunner on April 22, 2017, 01:18:07 am
Its in the March 2015 DSA 800 series User Manual page 161.  It was not in my original 2013 User Manual so I assumed added later in newer firmware.  I am running firmware v1.08 so I looked at the release notes from past firmware and it seems they added this after v 1.09.  Now I see they are up to 1.15 so maybe I should update the firmware.    Have to read how not to lose my 'licenses'.

Jerry NY2KW

OK.

Regarding your amplitude check, what sort of accuracy were you expecting to observe? Did you look at the specs of this unit?
Title: Re: Rigol DSA-815 - Amplitude calibration
Post by: K1JOS on April 22, 2017, 01:10:19 pm
The SA specs quote +/- 0.4 dB which I though were pretty good.  It turns out that my -1.5dB loss problem was not with the SA but with the 50 ohm coax cable... switching to a 'brand' name (though still made in China) brought things back to spec...actually within (-)0.25 dB of my NIST source.  Good lesson here, at least for me :-)

Jerry NY2KW
Title: Re: Rigol DSA-815 - Amplitude calibration
Post by: K1JOS on April 22, 2017, 01:11:29 pm
I still would like someone with the latest version firmware to check if there is an additional "Acc Calibrate" function. 

Jerry NY2KW
Title: Re: Rigol DSA-815 - Amplitude calibration
Post by: xrunner on April 22, 2017, 01:36:06 pm
The SA specs quote +/- 0.4 dB which I though were pretty good.  It turns out that my -1.5dB loss problem was not with the SA but with the 50 ohm coax cable... switching to a 'brand' name (though still made in China) brought things back to spec...actually within (-)0.25 dB of my NIST source.  Good lesson here, at least for me :-)

Jerry NY2KW

Yea I just checked mine @50 MHz 0 dBm with my Agilent 8648A (which isn't as accurate amplitude-wise as your source), but I get -0.48 dBm.

On the bad cables I say welcome to my world. I've had lot's on run-ins with poorly made cables and BNCs.  :(
Title: Re: Rigol DSA-815 - Amplitude calibration
Post by: Daruosha on April 22, 2017, 01:37:13 pm
I still would like someone with the latest version firmware to check if there is an additional "Acc Calibrate" function. 

Jerry NY2KW

Yes, there is.